I wish to be able to travel from Cambridge to Maidstone as a day return trip, leaving before 0830. My preferred route is via St Pancras and Strood to Maidstone West. However I want the option on the day of going via Victoria to Maidstone East or returning that way (for example if there are cancellations, or I fancy a change). The ticket I bought is an Anytime Day Return "valid via any permitted route" for £61.60. There is also an Anytime Day Return "not valid on HS1" for £58.30 which I didn't buy. I notice however that there is no + symbol denoting validity on the London Underground. Can I assume therefore the ticket is NOT valid for travel via Victoria? What if I used oyster to get between St Pancras and Victoria, would my Day Return ticket be accepted on the Victoria to Maidstone segment?